A video coding format (or sometimes video compression format) is a content representation format for storage or transmission of digital video content (such as in a data file or bitstream). It typically uses a standardized video compression algorithm, most commonly based on discrete cosine transform (DCT) coding and motion compensation. A specific software, firmware, or hardware implementation capable of compression or decompression to/from a specific video coding format is called a video codec. Some video coding formats are documented by a detailed technical specification document known as a video coding specification. Some such specifications are written and approved by standardization organizations as technical standards, and are thus known as a video coding standard. The term 'standard' is also sometimes used for de facto standards as well as formal standards. Video content encoded using a particular video coding format is normally bundled with an audio stream (encoded using an audio coding format) inside a multimedia container format such as AVI, MP4, FLV, RealMedia, or Matroska. As such, the user normally doesn't have a H.264 file, but instead has a .mp4 , which is an MP4 container containing H.264-encoded video, normally alongside AAC-encoded audio. Multimedia container formats can contain any one of a number of different video coding formats; for example the MP4 container format can contain video in either the MPEG-2 Part 2 or the H.264 video coding format, among others. Another example is the initial specification for the file type WebM, which specified the container format (Matroska), but also exactly which video (VP8) and audio (Vorbis) compression format is used inside the Matroska container, even though the Matroska container format itself is capable of containing other video coding formats (VP9 video and Opus audio support was later added to the WebM specification). A format is the layout plan for data produced or consumed by a codec. Although video coding formats such as H.